Equalizer valve cartridge assembly



Nov. 11, 1947. D, B, GARDINER EQUALIZER VALVE CARTRIDGE ASSEMBLY Filed Sept. 14, 1944 IN VEN TOR.

ATTORNEY DUNCAN BGARDINER I00 I02 BY Wi M Patented Nov. 11, 1947 EQUALIZER VALVE CARTRIDGE ASSEMBLY Duncan B. Gardiner, Detroit, Mich, assignor to Vickers Incorporated, Detroit, Micln, a corporation of Michigan Application September 14, 1944, Serial No. 554,023

4 Claims. (Cl. 303-54) This invention relates to power transmissions,

particularly tothose of the type comprising two or more fluid pressure energy translating devices, one of which may function as a pump and another as a fluid motor.

This invention is mor particularly concerned with power transmission systems adapted for use in applying selectively variable force to a load device such as a vehicle or aircraft brake.

In providing power-operated means for applying the brakes under manual control of larger aircraft, it is the practice to tap the main hydraulic power system operating main landing gear, wing flaps, etc. It is a problem to design an equalizing valve for such a system because system pressure is higher than can be safely utilized in hydraulic cylinders operating the brakes.

It is also a problem to overcome an unavoidable time lag between the depression of the foot pedal and the application of the brake due to the length and small size of the lines used. There is a tendency upon the part of the operator becaus of this time lag to further apply the brakes with a consequent grabbing of the brakes which may result in serious accident.

It is also a problem to design an equalizing valve which will give the operator a feel closely resembling the feel experienced by the operator of an automobile brake.

It is an object of the present invention to safely utilize power-operated means for manually applying the brakes of larger aircraft and, at the same time. to give the operator of such brakes a manual feel closely resembling the feel experienced by the operator of an automobile brake.

It is also an object of the present invention to provide a means overcoming the tendency of the operator to further apply the brakes because of an unavoidable time lag and thus solving the problem of grabbing brakes.

It is a further object of the present invention to provide an equalizing valve containing a unitary valve cartridge assembly of simplified construction which contains the main working parts of the equalizing valve, which cartridge may be easily assembled or disassembled. This makes it possible in case of excessive wear of one or more parts of such cartridge to easily remove the cartridge, replace the worn part or parts, reassemble and replace in such valve.

Further objects and advantagesv of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred form of the present invention is clearly shown. a

In the drawing:

Figure 1 is a diagrammatic view of a brake control circuit incorporating a. cross-sectional view of an equalizing valve incorporating a preferred embodiment of the present invention.

Figure 2 is'a longitudinal cross-sectional view of the unitary valve cartridge assembly.

Figure 3 is a view corresponding to Figure 2 showing the unitary valve cartridge assembly in the process of assembly.

Figure 4 is a fragmentary end view of a portion of the valve.

Referring now to Figure 1, there is shown a pump in which may be driven by any suitable means. such as an aircraft engine, not shown, which may withdraw fluid from a reservoir I2 by means of a suction conduit l4 and having a pump delivery conduit I6 connected to an unloading valve it. The unloading valve l8 will bypass pump delivery to the reservoir I2 by means of a return line 20 when the pressure in an accumulator 22 reaches a predetermined maximum.

The pump delivery conduit l6 extends and is: connected to the pressure port 24 of an equal-- izing valve 26. The equalizing valve 26 also con tains an exhaust port 28 and an operating chain-- ber port 30. A conduit 32 connected to operat-- ing chamber port 361s connected also to the head end of a cylinder 34 in which is mountel a slid'able piston 36 on a rod 38. Thepiston 3% is held in'its uppermost position by a spring 46. The rod end of the cylinder 34 is connected by a drain conduit 42 to the reservoir 12. The exhaust port 28 of the equalizing valve 26 is connected to the reservoir l2 by a conduit 44.

The equalizing valve 26 has a centrally stepped bore 46 connecting with the pressure port 24, operating chamber port 30 and exhaust port 28. Shiftable within the bore 46 is a hollow feel plunger 48 with shoulders 50 and 52 and having a passageway 49 therein aligned with the exhaust port 28. An exhaust valve seat insert 54, having a longitudinal stepped bore 56 forming at the smaller end of such bore an exhaust poppet seat 58, flts within the hollow feel plunger 48 so that a flange 60 of exhaust valve seat insert .54 rests on the shoulder 50 of the feel plunger 58.

With the exhaust valve seat insert 54 inserted in the bore 46 and thus connected to feel plunger 48, the longitudinal bore 46 of valve 26 is divided into two chambers, a, main spring chamber 62 and an operating chamber 64, with the only means of communication between the two chambers being bore 56 of exhaust valve seat insert 54.

Removably mounted in the bore 46 between exhaust valve seat insert 54 and an end cap 68 is a unitary valve cartridge 18 having a unitary valve 12, a first valve guide and spring retainer 14, a retainer member 16, a second valve guide 18, and a connecting spring 80.

. 3v Referring to Figures'a through 4,-the unitary ed and blocking communication to the main valve I2 is comprised ota rod 82 at one end of which is a pressure poppet 84 and at the other end of which is an exhaust poppet 84 smaller than the pressure poppet 84. The valve guide anddrilled passageways 88 and 88. The retainer.

member- I8 has acentrally stepped bore I80 having shoulders I02 and forming at its'sm'allest portion a pressure poppet seat I04. The'valve guide I8 has a bore I08 for receiving the central portion of valve I2 and drilled passageways I08 and H0.

In assembling the cartridge I0, as is more clearly illustrated in Figure 3. the valve guide 18 fits in the stepped bore I and rests on the shoulder I02 of the retainer member 18. The unitary valve I2 is inserted through the seat I04 of retainer member 18 and the slot 80 of valve guide 14, with the inner side of pressure poppet 84 resting on the pressure poppet seat I04. The connecting spring 80 is then placed over the unitary valve I2 on the unitary guide 14 and at this point, as is more clearly illustrated in Figure 3, the exhaust poppet 88 is inserted in either enlarged portion 82 or 84 of slot 80 and centered therein with the inner side of exhaust poppet 88 resting on slot 90. The cartridge assembly I0 fits into the longitudinal stepped bore 48 of valve 28 with the unitary valve guide and spring retainer 14 fitting around exhaust valve seat insert 54, with the flare 88 of guide I4 resting against the shoulder 52 of exenlarged portion of bore 48 and the whole carby the tridge assembly being held firmly in place end cap 68.

With the cartridge I0 thus inserted, the inner side of pressure poppet 84 is resting on the pressure poppet seat I04 and the outer side of the exhaust poppet 88 is slightly off of exhaust poppet seat 58, being maintained there by the action of spring 80. In this position, as illustrated in Figure 1, communication is established between the operating chamber 84 and exhaust port 28 by means of drilled passageways 88 and 88 and stepped bore I00 of exhaust valve seat insert 84.

A main operating spring II4 fits in the hollow of feel plunger 48 resting on flange 80 of exhaust valve seat insert 54. A spring abutment II8, containing a cavity II8, fits on the opposite end of main spring I I4. A control plunger I20, shiftable within a bore I22 of an end cap I24, fits into the cavity II8 of spring abutment H8. The end cap I24, fitting over abutment 8, holds main spring II4 securely in place.

Suitable linkage I28, connected to lever I28 which connects to th control plunger I20, is so arranged that, by depressing a foot pedal,'not shown, the control plunger I20 will be actuated.

Suitable packing rings designated I30 are provided at the points shown on the drawing to seal against fluid leakage. The end caps 88 and I24 are secured to the body of the equalizing valve 28 by suitable bolts.

In operation, with the pump I0 running and with fluid under pressure stored in the accumulatorv 22 and with the equalizer valve 28 in theposition illustrated in Figure 1, pressure poppet 84 .is seated on seat I04 and exhaust poppet 88 is slightly on from seat 88. In this position, fluid underpressure is unable to enter the equalizer valve 28because of pressure poppet 84 being seatoperating chamber 84. Spring 40 is able to hold piston 88 of cylinder 84 in'the upright position shown because of the absence of pressure in operating chamber 84 of valve 28. This absence of pressure is due to the fact that the exhaust poppet 88 is unseated which permits communication between the upper side of piston 88 and tank I2 by means or conduit 82. port 80, chamber 84,

bore 88, exhaust port 28 and conduit 44.

If the brake pedal is now depressed, lever I28, which is connected to the brake pedal by mechanical linkage, will actuate control plunger I20. The control plunger I20, which fits in a cavity of spring abutment I I8. will actuate main spring I I4. The main splilrffi tfl, which rests on the flange 80 of exhaust valve seatiinsert 84, will shift the feel plunger 48 because flange 80 of exhaust valve seat insert 84 rests on shoulder 80 of feel plunger 48. This movement of feelplunger 48 pushes the exhaust seat 88 onto exhaust poppet 88, thereby blocking communication between the operating chamber 84 and exhaust port 28, and establishes a thrust contact of the feel plunger 48 'with the unitary valve I2. a

The only opposition of the main operating spring II4 to pushing the exhaust seat 58 on the exhaust poppet 88 is the resistance of the cartridge-connecting spring 80 which is relatively slight. Once the exhaust seat 58 establishes contact with exhaust poppet 88, any further movement of feel plunger 48 which is shifted by main operating spring II4 will meet not only the resistance of the cartridge-connecting spring 80 but also the resistance of fluid under pressure acting against the pressure poppet 84. This is due to the fact that the pressure poppet 84 is at the other end of the connecting rod 82 of unitary valve I2, with the pressure poppet 84 being exposed to pressure from pressure port 24. When sufficient force has been exerted on the brake pedal to overcome the resistance of the cartridge-connecting spring and of pressure acting against pressure poppet seat area, main spring I I4 will actuate feel plunger 48 which has already established contact with the unitary valve 12, and the pressure poppet 84 will be pushed oil of its seat I04. When the pressure poppet 84 is unseated, fluid under pressure from accumulator 22 is permitted to enter the operating chamber 84 of valve 28 and is conducted to cylinder 34 by way of operating port 30 and conduit 32. Fluid is prevented from going to tank I2 because of exhaust poppet 88 being seated and blocking communication between operating chamber 84 and exhaust port 28.

It should be noted that, once the main operating spring II4 has overcome the resistance of the cartridge-connecting spring 80 and pressure acting against the pressure seat area and the pressure poppet 84 is unseated, fluid under pressure entering the operating chamber 84 of valve 28 will act on the entire area of feel plunger 48 within bore 48. When piston 38 of cylinder 34 has moved completely or the brake has been fully applied, any further increase of pressure in operating chamber 84 will further act against feel plunger 48, overcoming the resistance offered by main operating spring II4 and consequently will seat the pressure poppet 8,4.

When the brake is to be released. the brake pedal is retracted to permit main operating spring II4 to return to the position shown in Figure 1. As shoulder 82 of feel plunger 48 abuts the outer side of flare of guide I4 and shoulder 50 of feel plunger 48 abuts the inner side of flange 80 of exhaust valve seat insert 54, pressure in operating chamber 64 and also acting against pressure poppet 84 will return feel plunger 48 and exhaust valve seat insert 254. When the pressure poppet 84 becomes seated, however, exhaust poppet 86, which is still seated, wil1 finally unseat by action of spring 80. The spring 80, which abuts the inner side of flare 88 of guide 14, will shift guide l4, guide 14 will shift feel plunger 48, and feel plunger 48 will shift exhaust valve seat insert 54 containing exhaust valve seat 58 away from exhaust poppet 86, thereby unseating it. Thus, the cartridge-connecting spring 88 performs the double function of maintaining the members of the unitary valve cartridge assembly 18 in assembled position and that of returning feel plunger 48 and exhaust valve seat insert 54, thereby unseating exhaust poppet 88 when the brake is released.

When the feel plunger 48, which is connected to exhaust valve seat insert 54, has returned to the position shown in Figure 1, exhaust poppet 88 is slightly on of exhaust poppet seat 58 which establishes communication between the operating chamber 84 and tank I! by means of passageways 86 and 98 of guide 14, bore 56 of exhaust valve seat insert 54, main operating spring chamber 82, passageway 49 of feel plunger 48, exhaust port 28 and conduit 44. This permits fluid on the upper side of piston 88 to escape to tank l2 and,

with the release of pressure, spring 48 will return piston 36 to its uppermost position shown in Figure 1.

It should be noted that the main operating spring H4 which actuates the feel plunger 48 acts against fluid under pressure from accumulator 22, first against pressure poppet seat area and once the pressure poppet 84 has been pushed from its seat I84 against the full area of feel plunger 48 within bore 48. This results in an operator feel which is instantaneous and positive at all times,

whether the brake is being applied or released.

It should further be noted that the guide member 18 through which rod 82 is shiftable, being in alignment with the pressure and exhaust valve seats, assures positive seating of the valves and, because lateral movement of the rod is prevented, also prevents any violent movement to which the cartridge assembly is exposed from displacing the valves from their seats.

It should also be noted that the unitary valve cartridge III comprises a complete subassembly of interconnected members which are mutually self-supporting, independent of other fastening means of any nature. The cartridge and individual members of the same aredesigned and constructed to facilitate removal of the complete cartridge from the equalizing valve in case repair or replacement are necessary,

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is ,claimed is as follows:

1. A cartridge subassembly for an equalizing valve comprising mutually self-supporting members and having a unitary valve comprising a rod at each end of which is a head, one being smaller than the other, a spring retaining means having an opening with a head engaging portion at its center and with a larger portion'capable of passing over the smaller head of the valve, said larger portion being laterally displaced from. the head engaging portion, a second spring retaining means 6 having an opening abutting the inner side of the larger head of the valve, a guide member, through which the rod is perpendicularly shiftable, mounted in the second spring retaining means, and a spring maintaining all members in assembled position.

2. A cartridge subassembly for an equalizing valve comprising mutually self-supporting members and having a, unitary valve comprising a, rod at each end of which is a head, one being smaller than the other, a spring retaining means having an opening with a head engaging portion at its center and with a larger portion capable of passing over the smaller head of the valve, said larger portion being laterally displaced from the head engaging portion, a second spring retaining means having an opening forming a seat for and abutting the inner side of the larger head of the valve, a guide member having an opening in alignment with the head-engaging portion and the seat, respectively, of the first and second spring retaining means through which the rod is shiftable, and a spring maintaining all members in assembled position.

3. A cartridge subassembly for an equalizing valve comprising mutually self-supporting members and having a unitary valve comprising a rod at one end of which is formed a p pp t exhaust valve and at the other end a poppet pressure valve larger than the exhaust valve, a spring retaining means having an opening forming an exhaust valve seat at its center for engaging the exhaust valve and having a larger portion capable of passing over the exhaust valve laterally displaced from the exhaust valve seat, a second spring retaining means having an opening forming a pressure valve seat for engaging the inner side of the pressure valve, a guide member having an opening in alignment with the exhaust and pressure valve seats through which the rod is shiftable for insuring positive seating of the pressure and exhaust valves, and a spring maintaining all members in assembled position.

4. A cartridge subassembly for an equalizing valve comprising mutually self-supporting members and having a unitary valve comprising a rod at one end of which is formed a poppet exhaust valve and at the other end a poppet pressure valve larger than the exhaust valve, a spring retaining means having an opening forming an exhaust valve seat at its center for engaging the exhaust valve and having a larger portion capable of passing over the exhaust valve laterally displaced from the exhaust valve seat, a second spring retaining means having an opening forming a pressure valve seat for engaging the inner side of the pressure valve, a guide member mounted in the second spring retaining means having an opening in alignment with the exhaust and pressure valve seats through which the rod is shiftable for insuring positive seating of the pressure and exhaust valves, and a spring maintaining all members in assembled position.

DUNCAN B. GARDINER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PAThINTS Number Name Date 2,075,917 Vorech Apr. 6, 1937 2,266,817 Schober Dec, 23, 1941 1,420,898 Willey June 2'7, 1922 

